[2/2] riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings
Commit Message
When STRICT_KERNEL_RWX is set, any change of permissions on any kernel
mapping (vmalloc/modules/kernel text...etc) should be applied on its
linear mapping alias. The problem is that the riscv kernel uses huge
mappings for the linear mapping and walk_page_range_novma() does not
split those huge mappings.
So this patchset implements such split in order to apply fine-grained
permissions on the linear mapping.
Below is the difference before and after (the first PUD mapping is split
into PTE/PMD mappings):
Before:
---[ Linear mapping ]---
0xffffaf8000080000-0xffffaf8000200000 0x0000000080080000 1536K PTE D A G . . W R V
0xffffaf8000200000-0xffffaf8077c00000 0x0000000080200000 1914M PMD D A G . . W R V
0xffffaf8077c00000-0xffffaf8078800000 0x00000000f7c00000 12M PMD D A G . . . R V
0xffffaf8078800000-0xffffaf8078c00000 0x00000000f8800000 4M PMD D A G . . W R V
0xffffaf8078c00000-0xffffaf8079200000 0x00000000f8c00000 6M PMD D A G . . . R V
0xffffaf8079200000-0xffffaf807e600000 0x00000000f9200000 84M PMD D A G . . W R V
0xffffaf807e600000-0xffffaf807e716000 0x00000000fe600000 1112K PTE D A G . . W R V
0xffffaf807e717000-0xffffaf807e71a000 0x00000000fe717000 12K PTE D A G . . W R V
0xffffaf807e71d000-0xffffaf807e71e000 0x00000000fe71d000 4K PTE D A G . . W R V
0xffffaf807e722000-0xffffaf807e800000 0x00000000fe722000 888K PTE D A G . . W R V
0xffffaf807e800000-0xffffaf807fe00000 0x00000000fe800000 22M PMD D A G . . W R V
0xffffaf807fe00000-0xffffaf807ff54000 0x00000000ffe00000 1360K PTE D A G . . W R V
0xffffaf807ff55000-0xffffaf8080000000 0x00000000fff55000 684K PTE D A G . . W R V
0xffffaf8080000000-0xffffaf8400000000 0x0000000100000000 14G PUD D A G . . W R V
After:
---[ Linear mapping ]---
0xffffaf8000080000-0xffffaf8000200000 0x0000000080080000 1536K PTE D A G . . W R V
0xffffaf8000200000-0xffffaf8077c00000 0x0000000080200000 1914M PMD D A G . . W R V
0xffffaf8077c00000-0xffffaf8078800000 0x00000000f7c00000 12M PMD D A G . . . R V
0xffffaf8078800000-0xffffaf8078a00000 0x00000000f8800000 2M PMD D A G . . W R V
0xffffaf8078a00000-0xffffaf8078c00000 0x00000000f8a00000 2M PTE D A G . . W R V
0xffffaf8078c00000-0xffffaf8079200000 0x00000000f8c00000 6M PMD D A G . . . R V
0xffffaf8079200000-0xffffaf807e600000 0x00000000f9200000 84M PMD D A G . . W R V
0xffffaf807e600000-0xffffaf807e716000 0x00000000fe600000 1112K PTE D A G . . W R V
0xffffaf807e717000-0xffffaf807e71a000 0x00000000fe717000 12K PTE D A G . . W R V
0xffffaf807e71d000-0xffffaf807e71e000 0x00000000fe71d000 4K PTE D A G . . W R V
0xffffaf807e722000-0xffffaf807e800000 0x00000000fe722000 888K PTE D A G . . W R V
0xffffaf807e800000-0xffffaf807fe00000 0x00000000fe800000 22M PMD D A G . . W R V
0xffffaf807fe00000-0xffffaf807ff54000 0x00000000ffe00000 1360K PTE D A G . . W R V
0xffffaf807ff55000-0xffffaf8080000000 0x00000000fff55000 684K PTE D A G . . W R V
0xffffaf8080000000-0xffffaf8080800000 0x0000000100000000 8M PMD D A G . . W R V
0xffffaf8080800000-0xffffaf8080af6000 0x0000000100800000 3032K PTE D A G . . W R V
0xffffaf8080af6000-0xffffaf8080af8000 0x0000000100af6000 8K PTE D A G . X . R V
0xffffaf8080af8000-0xffffaf8080c00000 0x0000000100af8000 1056K PTE D A G . . W R V
0xffffaf8080c00000-0xffffaf8081a00000 0x0000000100c00000 14M PMD D A G . . W R V
0xffffaf8081a00000-0xffffaf8081a40000 0x0000000101a00000 256K PTE D A G . . W R V
0xffffaf8081a40000-0xffffaf8081a44000 0x0000000101a40000 16K PTE D A G . X . R V
0xffffaf8081a44000-0xffffaf8081a52000 0x0000000101a44000 56K PTE D A G . . W R V
0xffffaf8081a52000-0xffffaf8081a54000 0x0000000101a52000 8K PTE D A G . X . R V
...
0xffffaf809e800000-0xffffaf80c0000000 0x000000011e800000 536M PMD D A G . . W R V
0xffffaf80c0000000-0xffffaf8400000000 0x0000000140000000 13G PUD D A G . . W R V
Note that this also fixes memfd_secret() syscall which uses
set_direct_map_invalid_noflush() and set_direct_map_default_noflush() to
remove the pages from the linear mapping. Below is the kernel page table
while a memfd_secret() syscall is running, you can see all the !valid
page table entries in the linear mapping:
...
0xffffaf8082240000-0xffffaf8082241000 0x0000000102240000 4K PTE D A G . . W R .
0xffffaf8082241000-0xffffaf8082250000 0x0000000102241000 60K PTE D A G . . W R V
0xffffaf8082250000-0xffffaf8082252000 0x0000000102250000 8K PTE D A G . . W R .
0xffffaf8082252000-0xffffaf8082256000 0x0000000102252000 16K PTE D A G . . W R V
0xffffaf8082256000-0xffffaf8082257000 0x0000000102256000 4K PTE D A G . . W R .
0xffffaf8082257000-0xffffaf8082258000 0x0000000102257000 4K PTE D A G . . W R V
0xffffaf8082258000-0xffffaf8082259000 0x0000000102258000 4K PTE D A G . . W R .
0xffffaf8082259000-0xffffaf808225a000 0x0000000102259000 4K PTE D A G . . W R V
0xffffaf808225a000-0xffffaf808225c000 0x000000010225a000 8K PTE D A G . . W R .
0xffffaf808225c000-0xffffaf8082266000 0x000000010225c000 40K PTE D A G . . W R V
0xffffaf8082266000-0xffffaf8082268000 0x0000000102266000 8K PTE D A G . . W R .
0xffffaf8082268000-0xffffaf8082284000 0x0000000102268000 112K PTE D A G . . W R V
0xffffaf8082284000-0xffffaf8082288000 0x0000000102284000 16K PTE D A G . . W R .
0xffffaf8082288000-0xffffaf808229c000 0x0000000102288000 80K PTE D A G . . W R V
0xffffaf808229c000-0xffffaf80822a0000 0x000000010229c000 16K PTE D A G . . W R .
0xffffaf80822a0000-0xffffaf80822a5000 0x00000001022a0000 20K PTE D A G . . W R V
0xffffaf80822a5000-0xffffaf80822a6000 0x00000001022a5000 4K PTE D A G . . . R V
0xffffaf80822a6000-0xffffaf80822ab000 0x00000001022a6000 20K PTE D A G . . W R V
...
And when the memfd_secret() fd is released, the linear mapping is
correctly reset:
...
0xffffaf8082240000-0xffffaf80822a5000 0x0000000102240000 404K PTE D A G . . W R V
0xffffaf80822a5000-0xffffaf80822a6000 0x00000001022a5000 4K PTE D A G . . . R V
0xffffaf80822a6000-0xffffaf80822af000 0x00000001022a6000 36K PTE D A G . . W R V
...
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
---
arch/riscv/mm/pageattr.c | 263 ++++++++++++++++++++++++++++++++-------
1 file changed, 221 insertions(+), 42 deletions(-)
Comments
Hi Alexandre,
kernel test robot noticed the following build warnings:
[auto build test WARNING on linus/master]
[also build test WARNING on v6.6-rc4 next-20231006]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Alexandre-Ghiti/riscv-Don-t-use-PGD-entries-for-the-linear-mapping/20231006-173223
base: linus/master
patch link: https://lore.kernel.org/r/20231006092930.15850-3-alexghiti%40rivosinc.com
patch subject: [PATCH 2/2] riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings
config: riscv-rv32_defconfig (https://download.01.org/0day-ci/archive/20231007/202310070700.4hSXftFh-lkp@intel.com/config)
compiler: riscv32-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231007/202310070700.4hSXftFh-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310070700.4hSXftFh-lkp@intel.com/
All warnings (new ones prefixed by >>):
arch/riscv/mm/pageattr.c: In function '__split_linear_mapping_pmd':
arch/riscv/mm/pageattr.c:112:45: error: implicit declaration of function '_pmd_pfn'; did you mean 'pmd_pfn'? [-Werror=implicit-function-declaration]
112 | unsigned long pfn = _pmd_pfn(*pmdp);
| ^~~~~~~~
| pmd_pfn
arch/riscv/mm/pageattr.c:127:39: error: implicit declaration of function 'pfn_pmd'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration]
127 | set_pmd(pmdp, pfn_pmd(page_to_pfn(pte_page), PAGE_TABLE));
| ^~~~~~~
| pfn_pgd
arch/riscv/mm/pageattr.c:127:39: error: incompatible type for argument 2 of 'set_pmd'
127 | set_pmd(pmdp, pfn_pmd(page_to_pfn(pte_page), PAGE_TABLE));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| |
| int
In file included from include/linux/pgtable.h:6,
from include/linux/mm.h:29,
from include/linux/pagewalk.h:5,
from arch/riscv/mm/pageattr.c:6:
arch/riscv/include/asm/pgtable.h:249:47: note: expected 'pmd_t' but argument is of type 'int'
249 | static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
| ~~~~~~^~~
arch/riscv/mm/pageattr.c: In function '__split_linear_mapping_pud':
arch/riscv/mm/pageattr.c:152:45: error: implicit declaration of function '_pud_pfn'; did you mean 'pud_pfn'? [-Werror=implicit-function-declaration]
152 | unsigned long pfn = _pud_pfn(*pudp);
| ^~~~~~~~
| pud_pfn
arch/riscv/mm/pageattr.c:164:41: error: incompatible type for argument 2 of 'set_pmd'
164 | pfn_pmd(pfn + ((i * PMD_SIZE) >> PAGE_SHIFT), prot));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| |
| int
arch/riscv/include/asm/pgtable.h:249:47: note: expected 'pmd_t' but argument is of type 'int'
249 | static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
| ~~~~~~^~~
In file included from arch/riscv/include/asm/pgtable-32.h:9,
from arch/riscv/include/asm/pgtable.h:141:
arch/riscv/mm/pageattr.c:168:39: error: implicit declaration of function 'pfn_pud'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration]
168 | set_pud(pudp, pfn_pud(page_to_pfn(pmd_page), PAGE_TABLE));
| ^~~~~~~
include/asm-generic/pgtable-nopmd.h:44:86: note: in definition of macro 'set_pud'
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^~~~~~
>> include/asm-generic/pgtable-nopmd.h:44:76: warning: missing braces around initializer [-Wmissing-braces]
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^
arch/riscv/mm/pageattr.c:168:25: note: in expansion of macro 'set_pud'
168 | set_pud(pudp, pfn_pud(page_to_pfn(pmd_page), PAGE_TABLE));
| ^~~~~~~
arch/riscv/mm/pageattr.c: In function '__split_linear_mapping_p4d':
arch/riscv/mm/pageattr.c:201:45: error: implicit declaration of function '_p4d_pfn'; did you mean '_pgd_pfn'? [-Werror=implicit-function-declaration]
201 | unsigned long pfn = _p4d_pfn(*p4dp);
| ^~~~~~~~
| _pgd_pfn
>> include/asm-generic/pgtable-nopmd.h:44:76: warning: missing braces around initializer [-Wmissing-braces]
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^
arch/riscv/mm/pageattr.c:216:33: note: in expansion of macro 'set_pud'
216 | set_pud(pudp_new,
| ^~~~~~~
arch/riscv/mm/pageattr.c:226:39: error: implicit declaration of function 'pfn_p4d'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration]
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
include/asm-generic/pgtable-nopmd.h:44:86: note: in definition of macro 'set_pud'
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^~~~~~
arch/riscv/mm/pageattr.c:226:25: note: in expansion of macro 'set_p4d'
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
>> include/asm-generic/pgtable-nopud.h:40:60: warning: missing braces around initializer [-Wmissing-braces]
40 | #define set_p4d(p4dptr, p4dval) set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
| ^
include/asm-generic/pgtable-nopmd.h:44:86: note: in definition of macro 'set_pud'
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^~~~~~
arch/riscv/mm/pageattr.c:226:25: note: in expansion of macro 'set_p4d'
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
>> include/asm-generic/pgtable-nopmd.h:44:76: warning: missing braces around initializer [-Wmissing-braces]
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^
include/asm-generic/pgtable-nopud.h:40:33: note: in expansion of macro 'set_pud'
40 | #define set_p4d(p4dptr, p4dval) set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
| ^~~~~~~
arch/riscv/mm/pageattr.c:226:25: note: in expansion of macro 'set_p4d'
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
cc1: some warnings being treated as errors
vim +44 include/asm-generic/pgtable-nopmd.h
^1da177e4c3f41 Linus Torvalds 2005-04-16 39
^1da177e4c3f41 Linus Torvalds 2005-04-16 40 /*
^1da177e4c3f41 Linus Torvalds 2005-04-16 41 * (pmds are folded into puds so this doesn't get actually called,
^1da177e4c3f41 Linus Torvalds 2005-04-16 42 * but the define is needed for a generic inline function.)
^1da177e4c3f41 Linus Torvalds 2005-04-16 43 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 @44 #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
^1da177e4c3f41 Linus Torvalds 2005-04-16 45
Hi Alexandre,
kernel test robot noticed the following build errors:
[auto build test ERROR on linus/master]
[also build test ERROR on v6.6-rc4 next-20231006]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Alexandre-Ghiti/riscv-Don-t-use-PGD-entries-for-the-linear-mapping/20231006-173223
base: linus/master
patch link: https://lore.kernel.org/r/20231006092930.15850-3-alexghiti%40rivosinc.com
patch subject: [PATCH 2/2] riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings
config: riscv-rv32_defconfig (https://download.01.org/0day-ci/archive/20231007/202310071015.gtxGG3ml-lkp@intel.com/config)
compiler: riscv32-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231007/202310071015.gtxGG3ml-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310071015.gtxGG3ml-lkp@intel.com/
All errors (new ones prefixed by >>):
arch/riscv/mm/pageattr.c: In function '__split_linear_mapping_pmd':
>> arch/riscv/mm/pageattr.c:112:45: error: implicit declaration of function '_pmd_pfn'; did you mean 'pmd_pfn'? [-Werror=implicit-function-declaration]
112 | unsigned long pfn = _pmd_pfn(*pmdp);
| ^~~~~~~~
| pmd_pfn
>> arch/riscv/mm/pageattr.c:127:39: error: implicit declaration of function 'pfn_pmd'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration]
127 | set_pmd(pmdp, pfn_pmd(page_to_pfn(pte_page), PAGE_TABLE));
| ^~~~~~~
| pfn_pgd
>> arch/riscv/mm/pageattr.c:127:39: error: incompatible type for argument 2 of 'set_pmd'
127 | set_pmd(pmdp, pfn_pmd(page_to_pfn(pte_page), PAGE_TABLE));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| |
| int
In file included from include/linux/pgtable.h:6,
from include/linux/mm.h:29,
from include/linux/pagewalk.h:5,
from arch/riscv/mm/pageattr.c:6:
arch/riscv/include/asm/pgtable.h:249:47: note: expected 'pmd_t' but argument is of type 'int'
249 | static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
| ~~~~~~^~~
arch/riscv/mm/pageattr.c: In function '__split_linear_mapping_pud':
>> arch/riscv/mm/pageattr.c:152:45: error: implicit declaration of function '_pud_pfn'; did you mean 'pud_pfn'? [-Werror=implicit-function-declaration]
152 | unsigned long pfn = _pud_pfn(*pudp);
| ^~~~~~~~
| pud_pfn
arch/riscv/mm/pageattr.c:164:41: error: incompatible type for argument 2 of 'set_pmd'
164 | pfn_pmd(pfn + ((i * PMD_SIZE) >> PAGE_SHIFT), prot));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| |
| int
arch/riscv/include/asm/pgtable.h:249:47: note: expected 'pmd_t' but argument is of type 'int'
249 | static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
| ~~~~~~^~~
In file included from arch/riscv/include/asm/pgtable-32.h:9,
from arch/riscv/include/asm/pgtable.h:141:
>> arch/riscv/mm/pageattr.c:168:39: error: implicit declaration of function 'pfn_pud'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration]
168 | set_pud(pudp, pfn_pud(page_to_pfn(pmd_page), PAGE_TABLE));
| ^~~~~~~
include/asm-generic/pgtable-nopmd.h:44:86: note: in definition of macro 'set_pud'
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^~~~~~
include/asm-generic/pgtable-nopmd.h:44:76: warning: missing braces around initializer [-Wmissing-braces]
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^
arch/riscv/mm/pageattr.c:168:25: note: in expansion of macro 'set_pud'
168 | set_pud(pudp, pfn_pud(page_to_pfn(pmd_page), PAGE_TABLE));
| ^~~~~~~
arch/riscv/mm/pageattr.c: In function '__split_linear_mapping_p4d':
>> arch/riscv/mm/pageattr.c:201:45: error: implicit declaration of function '_p4d_pfn'; did you mean '_pgd_pfn'? [-Werror=implicit-function-declaration]
201 | unsigned long pfn = _p4d_pfn(*p4dp);
| ^~~~~~~~
| _pgd_pfn
include/asm-generic/pgtable-nopmd.h:44:76: warning: missing braces around initializer [-Wmissing-braces]
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^
arch/riscv/mm/pageattr.c:216:33: note: in expansion of macro 'set_pud'
216 | set_pud(pudp_new,
| ^~~~~~~
>> arch/riscv/mm/pageattr.c:226:39: error: implicit declaration of function 'pfn_p4d'; did you mean 'pfn_pgd'? [-Werror=implicit-function-declaration]
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
include/asm-generic/pgtable-nopmd.h:44:86: note: in definition of macro 'set_pud'
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^~~~~~
arch/riscv/mm/pageattr.c:226:25: note: in expansion of macro 'set_p4d'
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
include/asm-generic/pgtable-nopud.h:40:60: warning: missing braces around initializer [-Wmissing-braces]
40 | #define set_p4d(p4dptr, p4dval) set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
| ^
include/asm-generic/pgtable-nopmd.h:44:86: note: in definition of macro 'set_pud'
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^~~~~~
arch/riscv/mm/pageattr.c:226:25: note: in expansion of macro 'set_p4d'
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
include/asm-generic/pgtable-nopmd.h:44:76: warning: missing braces around initializer [-Wmissing-braces]
44 | #define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
| ^
include/asm-generic/pgtable-nopud.h:40:33: note: in expansion of macro 'set_pud'
40 | #define set_p4d(p4dptr, p4dval) set_pud((pud_t *)(p4dptr), (pud_t) { p4dval })
| ^~~~~~~
arch/riscv/mm/pageattr.c:226:25: note: in expansion of macro 'set_p4d'
226 | set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
| ^~~~~~~
cc1: some warnings being treated as errors
vim +112 arch/riscv/mm/pageattr.c
94
95 static int __split_linear_mapping_pmd(pud_t *pudp,
96 unsigned long vaddr, unsigned long end)
97 {
98 pmd_t *pmdp;
99 unsigned long next;
100
101 pmdp = pmd_offset(pudp, vaddr);
102
103 do {
104 next = pmd_addr_end(vaddr, end);
105
106 if (next - vaddr >= PMD_SIZE &&
107 vaddr <= (vaddr & PMD_MASK) && end >= next)
108 continue;
109
110 if (pmd_leaf(*pmdp)) {
111 struct page *pte_page;
> 112 unsigned long pfn = _pmd_pfn(*pmdp);
113 pgprot_t prot = __pgprot(pmd_val(*pmdp) & ~_PAGE_PFN_MASK);
114 pte_t *ptep_new;
115 int i;
116
117 pte_page = alloc_page(GFP_KERNEL);
118 if (!pte_page)
119 return -ENOMEM;
120
121 ptep_new = (pte_t *)page_address(pte_page);
122 for (i = 0; i < PTRS_PER_PTE; ++i, ++ptep_new)
123 set_pte(ptep_new, pfn_pte(pfn + i, prot));
124
125 smp_wmb();
126
> 127 set_pmd(pmdp, pfn_pmd(page_to_pfn(pte_page), PAGE_TABLE));
128 }
129 } while (pmdp++, vaddr = next, vaddr != end);
130
131 return 0;
132 }
133
134 static int __split_linear_mapping_pud(p4d_t *p4dp,
135 unsigned long vaddr, unsigned long end)
136 {
137 pud_t *pudp;
138 unsigned long next;
139 int ret;
140
141 pudp = pud_offset(p4dp, vaddr);
142
143 do {
144 next = pud_addr_end(vaddr, end);
145
146 if (next - vaddr >= PUD_SIZE &&
147 vaddr <= (vaddr & PUD_MASK) && end >= next)
148 continue;
149
150 if (pud_leaf(*pudp)) {
151 struct page *pmd_page;
> 152 unsigned long pfn = _pud_pfn(*pudp);
153 pgprot_t prot = __pgprot(pud_val(*pudp) & ~_PAGE_PFN_MASK);
154 pmd_t *pmdp_new;
155 int i;
156
157 pmd_page = alloc_page(GFP_KERNEL);
158 if (!pmd_page)
159 return -ENOMEM;
160
161 pmdp_new = (pmd_t *)page_address(pmd_page);
162 for (i = 0; i < PTRS_PER_PMD; ++i, ++pmdp_new)
163 set_pmd(pmdp_new,
164 pfn_pmd(pfn + ((i * PMD_SIZE) >> PAGE_SHIFT), prot));
165
166 smp_wmb();
167
> 168 set_pud(pudp, pfn_pud(page_to_pfn(pmd_page), PAGE_TABLE));
169 }
170
171 ret = __split_linear_mapping_pmd(pudp, vaddr, next);
172 if (ret)
173 return ret;
174 } while (pudp++, vaddr = next, vaddr != end);
175
176 return 0;
177 }
178
179 static int __split_linear_mapping_p4d(pgd_t *pgdp,
180 unsigned long vaddr, unsigned long end)
181 {
182 p4d_t *p4dp;
183 unsigned long next;
184 int ret;
185
186 p4dp = p4d_offset(pgdp, vaddr);
187
188 do {
189 next = p4d_addr_end(vaddr, end);
190
191 /*
192 * If [vaddr; end] contains [vaddr & P4D_MASK; next], we don't
193 * need to split, we'll change the protections on the whole P4D.
194 */
195 if (next - vaddr >= P4D_SIZE &&
196 vaddr <= (vaddr & P4D_MASK) && end >= next)
197 continue;
198
199 if (p4d_leaf(*p4dp)) {
200 struct page *pud_page;
> 201 unsigned long pfn = _p4d_pfn(*p4dp);
202 pgprot_t prot = __pgprot(p4d_val(*p4dp) & ~_PAGE_PFN_MASK);
203 pud_t *pudp_new;
204 int i;
205
206 pud_page = alloc_page(GFP_KERNEL);
207 if (!pud_page)
208 return -ENOMEM;
209
210 /*
211 * Fill the pud level with leaf puds that have the same
212 * protections as the leaf p4d.
213 */
214 pudp_new = (pud_t *)page_address(pud_page);
215 for (i = 0; i < PTRS_PER_PUD; ++i, ++pudp_new)
216 set_pud(pudp_new,
217 pfn_pud(pfn + ((i * PUD_SIZE) >> PAGE_SHIFT), prot));
218
219 /*
220 * Make sure the pud filling is not reordered with the
221 * p4d store which could result in seeing a partially
222 * filled pud level.
223 */
224 smp_wmb();
225
> 226 set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
227 }
228
229 ret = __split_linear_mapping_pud(p4dp, vaddr, next);
230 if (ret)
231 return ret;
232 } while (p4dp++, vaddr = next, vaddr != end);
233
234 return 0;
235 }
236
@@ -5,6 +5,7 @@
#include <linux/pagewalk.h>
#include <linux/pgtable.h>
+#include <linux/vmalloc.h>
#include <asm/tlbflush.h>
#include <asm/bitops.h>
#include <asm/set_memory.h>
@@ -25,19 +26,6 @@ static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
return new_val;
}
-static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
- unsigned long next, struct mm_walk *walk)
-{
- pgd_t val = READ_ONCE(*pgd);
-
- if (pgd_leaf(val)) {
- val = __pgd(set_pageattr_masks(pgd_val(val), walk));
- set_pgd(pgd, val);
- }
-
- return 0;
-}
-
static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
@@ -96,7 +84,6 @@ static int pageattr_pte_hole(unsigned long addr, unsigned long next,
}
static const struct mm_walk_ops pageattr_ops = {
- .pgd_entry = pageattr_pgd_entry,
.p4d_entry = pageattr_p4d_entry,
.pud_entry = pageattr_pud_entry,
.pmd_entry = pageattr_pmd_entry,
@@ -105,12 +92,179 @@ static const struct mm_walk_ops pageattr_ops = {
.walk_lock = PGWALK_RDLOCK,
};
+static int __split_linear_mapping_pmd(pud_t *pudp,
+ unsigned long vaddr, unsigned long end)
+{
+ pmd_t *pmdp;
+ unsigned long next;
+
+ pmdp = pmd_offset(pudp, vaddr);
+
+ do {
+ next = pmd_addr_end(vaddr, end);
+
+ if (next - vaddr >= PMD_SIZE &&
+ vaddr <= (vaddr & PMD_MASK) && end >= next)
+ continue;
+
+ if (pmd_leaf(*pmdp)) {
+ struct page *pte_page;
+ unsigned long pfn = _pmd_pfn(*pmdp);
+ pgprot_t prot = __pgprot(pmd_val(*pmdp) & ~_PAGE_PFN_MASK);
+ pte_t *ptep_new;
+ int i;
+
+ pte_page = alloc_page(GFP_KERNEL);
+ if (!pte_page)
+ return -ENOMEM;
+
+ ptep_new = (pte_t *)page_address(pte_page);
+ for (i = 0; i < PTRS_PER_PTE; ++i, ++ptep_new)
+ set_pte(ptep_new, pfn_pte(pfn + i, prot));
+
+ smp_wmb();
+
+ set_pmd(pmdp, pfn_pmd(page_to_pfn(pte_page), PAGE_TABLE));
+ }
+ } while (pmdp++, vaddr = next, vaddr != end);
+
+ return 0;
+}
+
+static int __split_linear_mapping_pud(p4d_t *p4dp,
+ unsigned long vaddr, unsigned long end)
+{
+ pud_t *pudp;
+ unsigned long next;
+ int ret;
+
+ pudp = pud_offset(p4dp, vaddr);
+
+ do {
+ next = pud_addr_end(vaddr, end);
+
+ if (next - vaddr >= PUD_SIZE &&
+ vaddr <= (vaddr & PUD_MASK) && end >= next)
+ continue;
+
+ if (pud_leaf(*pudp)) {
+ struct page *pmd_page;
+ unsigned long pfn = _pud_pfn(*pudp);
+ pgprot_t prot = __pgprot(pud_val(*pudp) & ~_PAGE_PFN_MASK);
+ pmd_t *pmdp_new;
+ int i;
+
+ pmd_page = alloc_page(GFP_KERNEL);
+ if (!pmd_page)
+ return -ENOMEM;
+
+ pmdp_new = (pmd_t *)page_address(pmd_page);
+ for (i = 0; i < PTRS_PER_PMD; ++i, ++pmdp_new)
+ set_pmd(pmdp_new,
+ pfn_pmd(pfn + ((i * PMD_SIZE) >> PAGE_SHIFT), prot));
+
+ smp_wmb();
+
+ set_pud(pudp, pfn_pud(page_to_pfn(pmd_page), PAGE_TABLE));
+ }
+
+ ret = __split_linear_mapping_pmd(pudp, vaddr, next);
+ if (ret)
+ return ret;
+ } while (pudp++, vaddr = next, vaddr != end);
+
+ return 0;
+}
+
+static int __split_linear_mapping_p4d(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end)
+{
+ p4d_t *p4dp;
+ unsigned long next;
+ int ret;
+
+ p4dp = p4d_offset(pgdp, vaddr);
+
+ do {
+ next = p4d_addr_end(vaddr, end);
+
+ /*
+ * If [vaddr; end] contains [vaddr & P4D_MASK; next], we don't
+ * need to split, we'll change the protections on the whole P4D.
+ */
+ if (next - vaddr >= P4D_SIZE &&
+ vaddr <= (vaddr & P4D_MASK) && end >= next)
+ continue;
+
+ if (p4d_leaf(*p4dp)) {
+ struct page *pud_page;
+ unsigned long pfn = _p4d_pfn(*p4dp);
+ pgprot_t prot = __pgprot(p4d_val(*p4dp) & ~_PAGE_PFN_MASK);
+ pud_t *pudp_new;
+ int i;
+
+ pud_page = alloc_page(GFP_KERNEL);
+ if (!pud_page)
+ return -ENOMEM;
+
+ /*
+ * Fill the pud level with leaf puds that have the same
+ * protections as the leaf p4d.
+ */
+ pudp_new = (pud_t *)page_address(pud_page);
+ for (i = 0; i < PTRS_PER_PUD; ++i, ++pudp_new)
+ set_pud(pudp_new,
+ pfn_pud(pfn + ((i * PUD_SIZE) >> PAGE_SHIFT), prot));
+
+ /*
+ * Make sure the pud filling is not reordered with the
+ * p4d store which could result in seeing a partially
+ * filled pud level.
+ */
+ smp_wmb();
+
+ set_p4d(p4dp, pfn_p4d(page_to_pfn(pud_page), PAGE_TABLE));
+ }
+
+ ret = __split_linear_mapping_pud(p4dp, vaddr, next);
+ if (ret)
+ return ret;
+ } while (p4dp++, vaddr = next, vaddr != end);
+
+ return 0;
+}
+
+static int __split_linear_mapping_pgd(pgd_t *pgdp,
+ unsigned long vaddr,
+ unsigned long end)
+{
+ unsigned long next;
+ int ret;
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+ /* We never use PGD mappings for the linear mapping */
+ ret = __split_linear_mapping_p4d(pgdp, vaddr, next);
+ if (ret)
+ return ret;
+ } while (pgdp++, vaddr = next, vaddr != end);
+
+ return 0;
+}
+
+static int split_linear_mapping(unsigned long start, unsigned long end)
+{
+ return __split_linear_mapping_pgd(pgd_offset_k(start), start, end);
+}
+
static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
pgprot_t clear_mask)
{
int ret;
unsigned long start = addr;
unsigned long end = start + PAGE_SIZE * numpages;
+ unsigned long lm_start;
+ unsigned long lm_end;
struct pageattr_masks masks = {
.set_mask = set_mask,
.clear_mask = clear_mask
@@ -120,11 +274,58 @@ static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
return 0;
mmap_write_lock(&init_mm);
+
+ /*
+ * We are about to change the permissions of a kernel mapping, we must
+ * apply the same changes to its linear mapping alias, which may imply
+ * splitting a huge mapping.
+ */
+
+ if (is_vmalloc_or_module_addr((void *)start)) {
+ struct vm_struct *area = NULL;
+ int i, page_start;
+
+ area = find_vm_area((void *)start);
+ page_start = (start - (unsigned long)area->addr) >> PAGE_SHIFT;
+
+ for (i = page_start; i < page_start + numpages; ++i) {
+ lm_start = (unsigned long)page_address(area->pages[i]);
+ lm_end = lm_start + PAGE_SIZE;
+
+ ret = split_linear_mapping(lm_start, lm_end);
+ if (ret)
+ goto unlock;
+
+ ret = walk_page_range_novma(&init_mm, lm_start, lm_end,
+ &pageattr_ops, NULL, &masks);
+ if (ret)
+ goto unlock;
+ }
+ } else if (is_kernel_mapping(start) || is_linear_mapping(start)) {
+ lm_start = (unsigned long)lm_alias(start);
+ lm_end = (unsigned long)lm_alias(end);
+
+ ret = split_linear_mapping(lm_start, lm_end);
+ if (ret)
+ goto unlock;
+
+ ret = walk_page_range_novma(&init_mm, lm_start, lm_end,
+ &pageattr_ops, NULL, &masks);
+ if (ret)
+ goto unlock;
+ }
+
ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
&masks);
- mmap_write_unlock(&init_mm);
- flush_tlb_kernel_range(start, end);
+unlock:
+ /*
+ * We can't use flush_tlb_kernel_range() here as we may have split a
+ * hugepage that is larger than that, so let's flush everything.
+ */
+ flush_tlb_all();
+
+ mmap_write_unlock(&init_mm);
return ret;
}
@@ -159,36 +360,14 @@ int set_memory_nx(unsigned long addr, int numpages)
int set_direct_map_invalid_noflush(struct page *page)
{
- int ret;
- unsigned long start = (unsigned long)page_address(page);
- unsigned long end = start + PAGE_SIZE;
- struct pageattr_masks masks = {
- .set_mask = __pgprot(0),
- .clear_mask = __pgprot(_PAGE_PRESENT)
- };
-
- mmap_read_lock(&init_mm);
- ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
- mmap_read_unlock(&init_mm);
-
- return ret;
+ return __set_memory((unsigned long)page_address(page), 1,
+ __pgprot(0), __pgprot(_PAGE_PRESENT));
}
int set_direct_map_default_noflush(struct page *page)
{
- int ret;
- unsigned long start = (unsigned long)page_address(page);
- unsigned long end = start + PAGE_SIZE;
- struct pageattr_masks masks = {
- .set_mask = PAGE_KERNEL,
- .clear_mask = __pgprot(0)
- };
-
- mmap_read_lock(&init_mm);
- ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
- mmap_read_unlock(&init_mm);
-
- return ret;
+ return __set_memory((unsigned long)page_address(page), 1,
+ PAGE_KERNEL, __pgprot(0));
}
#ifdef CONFIG_DEBUG_PAGEALLOC